;(function(global, utils){
	global.zwBack = function(delay){
		
		delay = delay || 50;
		setTimeout(function(){
			var params = utils.parseQuery(), url = '/?', keys;
			if(history.length == 1){
				keys = Object.keys(params);
				keys.forEach(function(key){
					if(utils.stickyParams.indexOf(key) > -1)
						url += key + '=' + params[key] + '&';
				});
				location.href = url;
			}else{
				history.back();
			}
		}, delay);
	}
	
})(typeof window !== 'undefined' ? window : this, utils);
